To calculate how much liquid remains for a particular item, WISK uses a combination of a few factors:

- Product's
*full weight*— weight of the item and its contents when it is full - Product's
*tare weight*— weight of the empty item excluding the liquid inside *Liquid's density*— necessary to convert weight into volume*Spout weight*— to account for the added weight of various spout types

Here is a simplified outline of the calculation process:

- Get the weight of the partially filled item from the Bluetooth scale and subtract any added weight from the spouts
- Check to see what the item's full weight is
- Check to see what the item's empty weight is — if we do not have the empty item weight, we can use the item's volume and the liquid's density to determine this
- Compare the full/empty item weights to the partial weight in (1) to determine the proportion of the item's contents that remain